A typical data storage system includes one or more arrays of magnetic disk drives or similar non-volatile storage devices, and a controller that controls the manner and locations in which data is written to and read from the devices. It is important that a host system be able to reliably access all of the data in the data storage system. However, a potential problem that affects data storage systems is that one or more of the devices and or a controller that manages data transfers to the various storage devices can fail or malfunction in a manner that prevents data from being persistently stored.
Most server computers provide low input/output latency memory storage in volatile memory elements using various dynamic random access memory or DRAM technologies. However, persistent data is required to quickly recover from a power event such as a loss of power. Some have taken the approach of deploying uninterruptable power supplies to ensure data stored in dynamic random access memory elements survives loss of power events. Some others add to the storage requirements and expense associated with providing and maintaining uninterruptable power supplies by introducing power generators which rely on fuel. These approaches fail to address data loss which occurs when a loss of power is encountered.